It is estimated that approximate 3% of the world's population is infected with hepatitis C virus (HCV). In developed countries, chronic hepatitis C is the leading cause for cirrhosis, hepatocellular carcinoma, and liver transplantation. The protease of hepatitis C virus is required for the cleavage of viral nonstructural polyprotein to form the mature virus and represents one of the attractive therapeutic targets for developing antiviral agents against HCV (Liu et al., 2004; Hepatitis C NS3 protease inhibition by peptidyl-a-ketoamide inhibitors: kinetic mechanism and structure. Arch Biochem Biophys 421: 207-216; Kakiuchi et al., 1999 A high throughput assay of the hepatitis C virus nonstructural protein 3 serine proteinase. J Virol 80: 77-84).
Human immunodeficiency virus (HIV) is the virus known to cause acquired immunodeficiency syndrome (AIDS) in humans and AIDS presents special problems to the medical community which the present invention addresses. Without treatment, immunodeficiency viral infection is highly lethal. Indeed, AIDS is the leading cause of human death. In certain parts of the world, such as sub-Saharan Africa, at least 10% of all adults are believed to be infected with HIV, with the prevalence in many capital cities believed to be 35% or more. In the United States, an estimated 800,000 to 900,000 people are currently infected with HIV, with approximately 40,000 new infections occurring each year. Of the more than 700,000 individuals in the United States who were infected with HIV as of December 2000, 58% have died.
The use of herbal therapy and folk medicines has been known for thousands of years in China. In fact, records on the use of herbs date back to biblical times. However, only recently have scientists begun exploring the possible role for herbs in treatment of viral infections. For example, extracts from the root of the Ecballium elaterium have been used to treat HCV and HBV (EP 0793964 and U.S. Pat. No. 5,648,089). While research in the field of herbal medicines has increased, much remains to be learned about the effectiveness of such herbal remedies.
The fruiting body of Antrodia cinnamomea T. T. Chang & W. N. Chou (a taxonomic synonym of Antrodia camphorate, referring to Wu et al., 1997, Antrodia camphorata (“niu-chang-chih”), new combination of a medicinal fungus in Taiwan. Bot. Bull. Acad. Sin. 38: 273-275) is a highly valued folk medicine in Taiwan. It is used as an antidote and for diarrhea, abdominal pain, hypertension, itchy skin, and liver cancer. Some bioactive constituents from the fruiting body of Antrodia cinnamomea have been isolated and characterized as a series of polysaccharides, steroids, triterpenoids, and sesquiterpene lactone (Lin et al., 2007, Factors affecting mycelial biomass and exopolysaccharide production in submerged cultivation of Antrodia cinnamomea using complex media. Bioresource Technology 98: 2511-2517). In previous studies, five new maleic and succinic acid derivatives (Compound 1-5) are isolated from the mycelium of Antrodia cinnamomea (Nakamura et al., 2004, Five new maleic and succinic acid derivatives from the mycelium of Antrodia comphorata and their cytotoxic effects on LLC tumor cell line. J Nat Prod 67: 46-48).
U.S. Pat. No. 7,109,232 discloses Compounds 1-5 from Antrodia cinnamomea and their uses such as hepatoprotection, anti-inflammation or anti-tumor activity and preparation. PCT Publication No. WO 2009/094807 A1 discloses Compounds 1-10 from Antrodia cinnamomea and their use for treating or prophylaxis of hepatitis C virus infection.
Traditionally, the fruit body of Antrodia cinnamomea has been used for liver cancer (Lin E S, Chen Y H. 2007. Factors affecting mycelial biomass and exopolysaccharide production in submerged cultivation of Antrodia cinnamomea using complex media. Bioresource Technology 98: 2511-2517). Polysaccharides of Antrodia cinnamomea has been show to have hepatoprotective effect (Han et al., 2006b, Protective effects of a neutral polysaccharide isolated from the mycelium of Antrodia cinnamomea on Propionibacterium acnes and lipopolysaccharide induced hepatic injury in mice. Chem Pharm Bull 54: 496-500) and anti-hepatitis B virus activity (Lee et. al., 2002, Antrodia camphorate polysaccharides exhibit anti-hepatitis B virus effects. FEMS Microbiol Lett 209:63-67). Of the maleic and succinic acid derivatives, Compound 3 showed protective activity in Propionicbacterium acnes and lipopolysaccharide treated mice (Nakamura N, Five new maleic and succinic acid derivatives from the mycelium of Antrodia comphorata and their cytotoxic effects on LLC tumor cell line. J Nat Prod 67: 46-48). Quantitative analysis showed that Compound 3 was the most abundant compound of this chemical type in the mycelium with a content of ca. 5% of the dry weight of mycelia (Han et al., 2006a, Protective effects of a neutral polysaccharide isolated from the mycelium of Antrodia cinnamomea on Propionibacterium acnes and lipopolysaccharide induced hepatic injury in mice. Chem Pharm Bull 54: 496-500).
During the investigation for anti HCV agents from natural source, compounds isolated from Antrodia cinnamomea showed variable activities (PCT publication No. WO 2009/094807). The highest was compound 1 (0.9 μg/mL), compound 3 (2.9 μg/mL). Compound 2 shows low activity, although it is sharing the main nucleus with other compounds. Therefore a series of derivatives was carried out, in this study, for Compound 2 targeting to improve its activity as anti HCV protease agent. Also, a new isolated compound from Antrodia cinnamomea was investigated its activity as anti HCV or HIV-1 protease agent.